Field-emission electron source for vacuum micropump

In the work a conception of a miniature, orbitron ion vacuum micropump for an integration with vacuum MEMS devices is presented. It is made of silicon and glass using microengineering technology. The main part of the device is a lateral field-emission source of electrons, which has been fabricated on oxidized silicon wafer. Both, cold cathode and anode of the source are made of thin gold layer using only one photolithography process. Fabrication process and the preliminary results of electrical tests of the field-emission electron source are presented. Experimental studies have shown its good emission parameters: a low threshold voltage (over a dozen Volts), a high electron current (from tens to several hundred micro amperes), and field enhancement coefficient from 107 to 108 cm−1. These results are promising and give possibility to fabricate orbitron micropump as an integrated part of vacuum MEMS.

► A field-emission electron source made of nanometer thin gold layer has been fabricated and measured. ► Satisfactory results (low threshold voltage −15 V, high emission current – micro to milliamperes) and good stability has been obtained. ► It was possible to control the anode current with gate polarization. ► The presented electron source will be able to work in vacuum MEMS devices (like miniature orbitron pump).